岩豆凝集素寡糖链的研究

COMPOSITION ANALYSIS OF THE OLIGOSACCHARIDES OF MILLETTIA DIELSIANA HARMS LECTIN

用肼解法释放了岩豆凝集素（ＭＤＬ）的寡糖链，经离子交换柱层析和滤纸层析除去肽链和其它小分子物质，所获得的寡糖部分，以ＮａＢＨ＿４还原，得到还原末端为Ｎ－乙酰氨基葡萄糖醇的寡糖链。再经Ｂｉｏ－ＧｅｌＰ－４凝胶柱过滤，可以从ＭＤＬ分离出两个寡糖链。此纯化的两个寡糖链经甲醇－盐酸水解，最后制备三甲基硅醚衍生物，用气相色诸法分析其糖基组成。分析结果表明；ＭＤＬ分子中含有以Ｎ－型糖苷键连接的两条算糖链，其糖基组成分别为：Ｍａｎ＿６Ｆｕｃ＿１ＧｌｃＮＡｃ＿２和Ｍａｎ＿４Ｆｕｃ＿１ＧｌｃＮＡｃ＿２。

tetract In the structural studies of oligosaccharides in glycoproteins,one of the biggestproblems is to obtain the purified sugar chains. Here in we reported that hydrazinolysis had beenused for releasing the Asparagine-linked sugar chains,ion-exchang and paper chromatography forremoving the peptides and lower molecular portion,the oligosaccharides were then reduced byNaBH_4 to obtain oligosaccharides with N-acetyl-aminoglucositol at the reducing end,which could befractionated by apssing through a Bio-gel P-4 column, and two oligosacchrides could be separated.these two portions were methanolysed and finally transformed into derivatives of trimethylsilane. Atlast, gas chromatography of these two derivatives showed that these two oligosaccharides wereMan_6 Fuc_1 GlcNAc_2 and Man_4 Fuc_1 GlcNAc_2 respectively.